How to have password echoed as asterisks

Question

I'm trying make a login window where a user is prompted to enter their Username and Password, although when the password is entered I am looking for asterisks to be printed, like common password entry (i.e. - Sekr3t is echo'd as: * * * * * *).

Here's the code I have so far, and I can't figure out why it doesn't echo asterisks:

import msvcrt
import sys

def login(prompt = '> '):
   write = sys.stdout.write
   
   for x in prompt:
       msvcrt.putch(x)
   passw = ""
   
   while 1:
       x = msvcrt.getch()
       if x == '\r' or x == '\n':
           break
       if x == '\b':
           # position of my error
           passw = passw[:-1]
       else:
           write('*')
           passw = passw + x
   msvcrt.putch('\r')
   msvcrt.putch('\n')
   return passw

Any help would be appreciated.

Solution

You should be able to erase an asterisk by writing the characters \x08 \x08. The \x08 will move the cursor back one position, the space will overwrite the asterisk, then the last \x08 will move the cursor back again, putting it in the correct position to write the next *.

I don't know off the top of my head how to determine when a backspace is typed, but you can do that easily: just add something like print repr(x) after you've called x = msvcrt.getch(), then start your program and hit backspace.